Sewing Machine Thread Take-Up Mechanism for Compact Cylinder Bed
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Solution Overview
Problem
Conventional sewing machines require a picker and additional components, increasing the size and production cost, while also limiting the sewable area due to the necessity of a picker and the synchronization of thread take-up with the cutting mechanism, which can be affected by the material of the workpiece cloth or needle thread.
Innovation Solution
A sewing machine design that eliminates the need for a picker by incorporating a thread take-up mechanism, a fixed and movable cutting blade, a thread wiper, and a control device to securely manage the needle thread after cutting, ensuring a predetermined amount of thread is secured without a picker or additional motor, thus reducing the size of the cylinder bed and increasing the sewable area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a picker is disposed in front of the rotary hook to secure the needle thread, then the needle thread can be retained reliably, but the front end of the cylinder bed must be extended, increasing the distance from the sewing needle to the cylinder bed and narrowing the sewable area
Solution Approach 1:
The invention removes the picker component from the cylinder bed front end, extracting the function of needle thread retention to the thread take-up mechanism instead. This eliminates the need to extend the cylinder bed front end, thereby maintaining a compact structure and preserving the sewable area while still achieving reliable thread retention through the modified thread take-up operation.
Solution Approach 2:
The thread take-up mechanism is given multiple functions: it not only performs its traditional role of winding thread but also secures the needle thread after cutting by operating in coordination with the cutting blade. This multi-functionality eliminates the need for a separate picker component, reducing device complexity while maintaining thread retention reliability.
2Reliability
If a picker driving motor and linking member are added to control the picker, then the needle thread can be secured, but the number of components increases and the production cost increases
Solution Approach 1:
The invention merges the needle thread retention function into the existing thread take-up mechanism, combining multiple functions (thread winding and thread retention) into a single mechanism. This eliminates the need for separate picker, picker driving motor, and linking member components, thereby reducing device complexity and production cost while maintaining reliable thread retention through coordinated operation with the cutting blade.
Solution Approach 2:
The thread take-up mechanism serves dual purposes: traditional thread winding and post-cutting thread retention. By making this single mechanism multi-functional, the invention eliminates the need for additional dedicated components like the picker and its driving mechanism, thus reducing the overall number of components and production cost.
3Device complexity
If the timing of the cutting blade return movement is synchronized with the thread take-up rise, then no picker is needed, but the amount of remaining needle thread is adversely affected by the material of workpiece cloth or needle thread
Solution Approach 1:
The invention performs the thread retention action in advance by operating the thread take-up to secure the needle thread before the cutting blade completes its return movement. This preliminary action ensures that the thread is reliably retained regardless of material properties, eliminating the dependency on precise timing synchronization between the cutting blade and thread take-up that plagues conventional designs.
Data Source
AI summary
In a sewing machine, a control device is configured to execute a needle thread cutting operation including driving a movable cutting blade to a predetermined pivot location, driving a wiper driving mechanism for protruding a wiper by a predetermined stroke, driving the thread take-up driving mechanism to lower the thread take-up by a predetermined distance, driving a wiper driving mechanism to draw back the wiper by a predetermined amount corresponding to the lowering of the thread take-up, driving the movable cutting blade to a standby position, driving the thread tension adjusting mechanism to release a thread tension adjusting mechanism, and driving the thread take-up driving mechanism to move the thread take-up to an original uppermost position.